        (filter (comp not nil?))))                           ;; of the 9 items, there should be only 3 non-nil matches coresponding to  H : M
 
 
-(defn- text->time
+(defn text->time
   "return as a time int, the contents of 'text'"
   [text]
   (->> text

       triple->time))                                       ;; turn the triple of values into a single int


(defn- time->text
  "return a string of format HH:MM for 'time'"
  [time]
  (let [hrs  (time->hrs  time)
        mins (time->mins time)]
    (str (pad-zero-number hrs 2) ":" (pad-zero-number mins 2))))

(defn- valid-text?
  "Return true if text passes basic time validation.
   Can't do to much validation because user input might not be finished.
   Why?  On the way to entering 6:30, you must pass through the invalid state of '63'.

  [text]
  (= 3 (count (extract-triple-from-text text))))

(defn valid-time?
  [time]
  (cond
    (nil? time) false                                       ;; can't be nil
